F I N E W O O D W O R K I N G80 Photos: Mark Schofield

Preparation Priming Painting

Three Steps to a Flawless

Painted Finish

B Y P A U L S N Y D E R

If you associate the word “paint” with images of a pail of house paint, a roller, and a brush, you may have difficulty linking it to fine furniture. However, painted built-in cabinets,

bookcases, wall units, and furniture are as popular today as they have ever been, and a great paint job stands comparison with the best clear finish.

There is more to achieving a quality painted finish than meets the eye, and the process is different than obtaining a clear finish. Much of the effort centers on the need for a perfectly flat, smooth base for the paint. To get this base, I work through a series of preparation and priming steps that get the surface of the piece progressively smoother.

Because the wood will be hidden under paint, it doesn’t make sense to use expensive furniture-grade hardwoods, such as oak, ash, walnut, and mahogany. Poplar, medium-density fiberboard (MDF), birch plywood, pine, and paint-grade alder and maple are more suitable for painting. Paint grade just means the wood

has grain or color variations that make it unsuitable for a clear or stained finish.

Surface preparation is criticalGetting the wood ready for painting is even more important than preparing it for a clear finish, despite the fact that any repairs will be hidden under the paint. The first step is to inspect all of the surfaces and fill any holes, cracks, and gaps, and remove any glue runs or drips.

Once the filler is dry (for more on the different types of fillers, see the story above), sand the wood with P150-grit paper. This grade of paper levels the surface and makes it uniform, but leaves it relatively rough so that the primer still has some “tooth” to latch onto. As you sand each surface, start with any areas that were filled; excess filler will create a high spot that will show up later in the finish. However, filler used in large holes might shrink, leaving a recess that will need to be filled and sanded again.

Pay attention to end grain, edges, and profiles—End grain will soak up a lot of primer if you don’t pretreat it. Either seal end grain with glue size, shellac, glazing putty, or spackle and

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Fillers under a painted finish

don’t need to blend into the wood,

but they shouldn’t shrink as they

dry, leaving a low spot that must

be refilled. Use fillers that are

easy to sand. I also prefer fillers

that dry fast.

Some of the best painted

finishes are on cars, and auto-

supply shops sell fillers that will

help you achieve such quality. For

fine cracks, flat end grain, and

flat MDF edges, automotive spot

and glazing putty works well.

Spackle is a good choice

on flat or routed end grain and

MDF profiles. However, spackle

shouldn’t be used to fill a deep

hole; sanding it can leave a de-

pression in the surface of the

piece. Spackle also dries

a lot more slowly than

other fillers, so use it

sparingly.

Preparation A filler for every blemish

A smooth surface. Large holes are best filled with an auto-body filler that must be mixed with a hardener (far left). Fast-drying wood filler is ideal for medium-size holes (near left).

When MDF is cut or routed,

a rough, porous surface is

exposed. The best way to fill

and smooth it is to cover the

area with spackle, and then

use a small, dampened brush

with the bristles cut short

to work the excess spackle

out of the corners and curves

before it has a chance to

harden. Once the spackle

dries, smooth it with a sand-

ing sponge that can be shaped to fit into the profile.

Avoid using a water-based primer on MDF, which can cause

the fibers to swell and leave the surface bumpy. Instead, choose

an oil-based primer or alcohol-based shellac.

Tips for MDFTips for MDF

Primer should be compatible

with the topcoats and ad-

here well to both the wood

and the topcoats. The primer

also should fill the grain,

leaving the surface flat, as

well as dry quickly and sand

easily. If you’ll be using a

water-based topcoat, choose

a 100% acrylic primer.

There are situations

when another type of primer

is preferred. On areas prone

to staining—wood knots,

sap streaks, tannins, and

pitch—shellac is the best

choice. To simply seal the

wood, use clear shellac, but

to seal and prime the wood,

use pigmented shellac such

as Zinnser’s BIN.

If the paint you’re using

contrasts a lot with white

primer, tint the primer to a

color close to the paint. The

paint will obscure the tinted

primer with fewer coats,

and if the finish is scratched

or otherwise damaged, the

primer will be less visible.

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then sand it smooth; or sand the edges with P220- or higher-grit sandpaper to burnish the surface, which will prevent the primer from soaking in too deeply.

On routed profiles, the aim is to achieve a smooth surface but still retain the crispness of the profile. Automotive glazing putty dries too fast, and glue size is relatively difficult to sand; like shel-lac, glue size doesn’t fill the many small voids that cause a rough texture. I’ve found that the best filler for profiles is spackle (for more on using spackle, see “Tips for MDF” on p. 81) because it is easy to use and easy to shape when dry. Spackle is especially well suited for filling mitered corners in crown molding, where

the detail and location call for a filler that can be spread easily and then sanded.

Break the corners for a better surface—The final preparation is to lightly sand the sharp corners, rounding them over slightly. Known as breaking the corners, this step helps paint flow from a flat surface onto a corner, avoiding paint buildup. It also reduces the chances of sanding through the primer on the corners.

Primer readies a smooth surface for the topcoatsWith the obvious defects filled, everything sanded, and the corners

broken, it’s time to prime. Don’t think of primer as being optional; it’s indispensable for the flat, smooth base necessary for a painted finish. Primer performs a variety of functions that either the paint itself doesn’t do or the primer does better.

The first coat of primer may be ab-sorbed unevenly—Apply an even coat of primer using the brushing techniques described in FWW #156 (“Choosing and Using Brushes,” pp. 38-43). With MDF and maple, one coat of primer often is all that’s needed because the substrate is dense and free of pores. Other woods usually take two coats and sometimes three.

Despite the extra preparation on end grain and profiles, these areas still may absorb an excess of primer. The natural instinct is to apply it more heavily to get continuous, even coverage. But applying primer thickly leads to sags and runs and

Priming Select a compatible primer

I use a clear sealer when I’m painting a

piece that’s made of wood suitable for a

stained or clear-coat finish (e.g., pine).

Applying the sealer makes it easier to

strip paint from the piece if someone

ever wants to change the look; it’s hard

to remove every last trace of the pig-

ments when primer or paint is applied

to bare wood. An alternative to alcohol-

based shellac is a water-based shellac

such as Ultra-Seal from Target Coatings.

It can be sprayed safely and cleans up

with warm, soapy water.

Seal before primingSeal before priming

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also slows the drying time. A better option is to apply primer in several thin coats until you get uniform coverage.

Once the primer dries, it’s time to find and fix all of the surface flaws that this first coat has revealed. Each little hole, crack, and other imperfection that you didn’t see during the surface prepara-tion stands out clearly after the first coat of primer.

Filling, sanding, and applying the next coat of primer—If you need to make minor repairs, and you are working with MDF or a tight-grained wood such as maple, sand the whole surface carefully after the filler dries; use P220 grit on a sanding block or a random-orbit sander. If the primer has soaked in a lot, or if there’s a strong grain pattern, the entire surface will need a vigor-ous sanding, which means you may end up removing most of the primer. If the grain is visible, use P150 grit, sanding until either the wood begins to show through the primer or all the shiny dimples (low spots) on the surface disappear. Use a random-orbit sander on large, flat areas, but on narrow boards, molding, or inside cor-ners, use a sanding sponge. To avoid cutting through the edges and corners on narrow pieces, fold the sponge to fit the width.

With everything sanded, remove the dust and feel the surface with your fingers. Sand any rough areas again as needed. If there are bare spots, prime and sand them again. Then apply a second coat of primer over the entire surface. Sand this additional coat

Apply the first coat of primer. Brush on an even coat. On areas that will absorb the primer, let this coat dry and then apply a second coat.

Sand the primer. Depending on how rough the surface is, sand the first coat of primer using P150- or P220-grit paper on a random-orbit sander. A sanding sponge is a good choice for smoothing moldings.

Fill small blemishes. The first coat of primer reveals surface imperfections that may have been missed during the initial preparation.

Paint for interior cabinetry and fur-

niture should be formulated to resist

sags and runs, and it should dry fast to

avoid excessive dust collection. It also

should provide a completely opaque

finish after two coats and be durable

enough for the intended use of the

piece. Don’t be tempted to economize

with a $15 can of paint from a home

center; quality is indicated by price,

so be prepared to pay

upwards of $30 per

gallon for paint used by

the pros.

There are a number

of quality 100% acrylic

and acrylic-enamel

house paints. Generally

speaking, manufactur-

ers use the term enam-

el to describe any paint

that has a smooth, hard surface. Add

a few ounces of Floetrol, a latex paint

additive that improves flow-out and lev-

eling, to each gallon you use.

A good paint deserves a good

brush. Pay extra for a quality nylon

brush with flagged ends (the bristle

ends are split). Nylon is softer than

polyester or polyester/nylon blends

and will help the paint lay down more

smoothly with fewer

brush-stroke ridges. The

flagged ends will leave a

finer, smoother pattern.

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with P220-grit paper and a fine sanding sponge, working carefully to avoid cutting through the primer. When you’re finished, remove the dust and inspect the surface to make sure all of the problem areas have been addressed. The surface should look as defect-free as you want the final painted finish to look. If you sanded through to bare wood, prime and sand only those areas again.

Two tinted topcoats are protected by a clear coatNow that all of the hard work is done, it’s time to paint. If more than a day has passed since you last sanded the primed surfaces, go over them quickly and lightly with P220-grit sandpaper. Like other finishes, primer continues to

cure for a number of days, so the sanding scratches tend to shrink and close, reducing the bond between primer and paint.

If the paint is tinted and you have more than one can, mix them all together in an empty paint bucket to ensure the same color throughout the job. Then pour the paint into a smaller container with a large opening until it’s half full. Dip the brush into the paint no more than halfway up the bristles, and gently tap them on the inside wall of the container to remove excess paint.

Brush with the grain in long strokes, holding the paintbrush at about a 45º angle to the surface. Overlap strokes slightly to maintain a wet edge and apply light pressure to keep all of the

bristles in contact with the surface. Pull up as you reach the end of a stroke to avoid leaving a ridge. On long surfaces where you need to apply the paint in sections, start a new section just beyond the last strip and brush back into the wet section. Starting in the wet section causes pooling.

Plan to use two coats of paint. Trying to obtain 100% coverage with one coat encourages applying the paint too thickly. Scuff-sand between coats to promote good adhesion, and allow the paint to dry for at least two weeks to reach optimal durability before putting the piece to use.

Clear coat the paint—After letting the second coat of paint dry for 24 hours, you can apply a coat of clear finish for improved durability, added depth, and optional sheen adjustment.

The texture of the painted surface and the final sheen determine how much sanding is needed

Painting Pay top dollar for the topcoat

Try to paint horizontally. It is easier to get a good finish with no sags or runs if you paint surfaces when they are horizontal.

Spraying is the quickest and

easiest way to get a smooth,

high-quality finish. I use high-

volume, low-pressure (HVLP)

spray equipment and select a

paint designed for spray applica-

tion. A couple of good brands

are Target Coatings and M.L.

Campbell.

Paints designed for sprayingPaints designed for spraying

before the clear coat. If the surface is flat and you’re planning on a satin or semigloss clear coat, then a light scuff-sanding is fine. If there are substantial brush ridges, or if you want a high gloss, the paint should be sanded until it is level.

For hand-sanding, use sanding sponges. Their padding helps to avoid cutting through the paint. For larger flat surfaces, Mirka’s Abralon abrasive pads can be attached to a random-orbit sander to make the job faster.

To minimize changes in color, the clear coat should be com-pletely clear, nonyellowing, and compatible with the paint. A water-based polyurethane is a good choice. You will be rewarded with a painted finish every bit as attractive as the finest clear finish.

Paul Snyder is a professional finisher near Fredericksburg, Va.

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Choose the right brush. Use a 2-in. or 21⁄2-in. angled brush to get into small or confined areas (above). Switch to a 3-in. brush for large panels (left), and apply the paint in long, flowing strokes.

Sand between coats. Use a fine sanding sponge to smooth the first topcoat. Don’t worry about sanding through to the prim-er in some spots; it is more important to get a smooth surface.

F O R P E R F E C T R E S U LT S

Applying a clear coat

protects the paint

and gives a look of

greater depth. To

minimize changes in

color, the clear coat

should be completely

clear, nonyellowing,

and compatible with

the paint.

A clear coat is optionalA clear coat is optional